Focusing on Flame Blade...

[BadBird]

So how would people here set out to build a character specializing in actually using Flame Blade? The best I've come up with so far would be:

Empowered Flame Blade as a level 3 spell with a metamagic trait: 1d8+1/2levels, x1.5.

Shaman for Divine Favor/Power and Flame Blade on one spell list.

Spirit of Battle for Weapon Specialization: Scimitar and Enemies' Bane.

One level of Monk plus the Witch Doctor Shaman Archetype to get Crusader's Flurry: Scimitar.

So when you get the Battle Spirit stuff together at level 9:
(1d8+4)x1.5 = 12.75; +4 Divine Favor, +2 Weapon Specialization, +2+2d6 Bane = 27.75, full attack for 4 strikes with flurry/haste.

Naturally, Elemental Spell metamagic (or rod) as well...

[Starbuck_II]

Too bad you aren't Sorc 1 as well, they can add 1 Force damage to any attack damage as a trait (this would include Flame Blade).

If fighting high SR creatures, you might want Piercing (+1) since Flame Blade has SR.

Furious Metamagic (+1) can add 2x spell Level to damage (adding heighten would increase this): main use is to let you cast while raging, but the bonus of spell is decent.

Burning Spell (+2) does Furious's amount of damage next round (they are burning). But since it is +2 and Furious is +1, Furious seems better unless using cleave to hit every enemy once.

[SmiloDan]

Can you add produce fire damage to a flame blade?

I think there is a druid archetype that gives sneak attack.

Also, lots of rogue and/or ninja levels add sneak attack.

Your best bet might be a wand of flame blade with 20 levels of rogue or ninja and Use Magic Device. Tons of sneak attack damage, attacking flatfooted touch AC while flanking.

[BadBird]

Metamagic has some really interesting uses beyond Empower, but since Empower already makes it level 3 it starts to get really costly to stack up more. Piercing Spell is probably a given to make sure SR doesn't get troublesome, which brings it up to 4; beyond that I don't know if there's much really worth it.

I hadn't thought of Nature Fang Druid. Studied Target is definitely attractive, though it's a pain that it's not a swift action until 9. Overall I don't think it brings quite as much as Shaman does with Divine Favor and Battle Spirit - it's a pity it replaces Wild Shape, since a Fire Elemental form using Flame Blade and Burn would be pretty great. Maybe I should be looking at a Fire Elemental Druid... I'd just want some kind of Druid Channel Energy.

Sneak Attack is another interesting thought I hadn't really considered. It's a major source of damage, but I don't think it's quite worth it when the trade-off is that Flame Blade is weak and short duration.

Actually, thinking on Druid... maybe an Arctic Druid with Arctic Domain (for channel) that turns into a Fire Elemental and eventually uses the Snowcaster ability to create (Cold) Flame Blade with Rime Spell? A Fire Elemental wielding a blade of burning cold is some pretty flavorful stuff, if nothing else.

[Derrick Winters]

I'd recommend a Paladin - Sacred Servant of Sarenrae.

According to the Unique Spell Rules for Paladins of Sarenrae, you can cast Flame Blade as 2nd-level spell.

With the Feat Energy Channel and the Fire Domain(from the Sacred Servant Archetype), you can add (Number of Channel Dice) x2 as bonus fire damage for your next three attacks.

As Sacred Servant, you can choose your divine bond bonus such that your number of channel energy dice is improved.

Example:

7th-level Paladin(Sacred Servant of Sarenrae)
He has Channel Energy(4d6) normally; if he activates his divine Bond, he can improve that to 5d6 for 7 minutes.

If he uses his Energy Channel feat as a swift action, he adds +8 (or +10 if divine bond is active) fire damage to his next three attacks.

So he could cast Flame Blade, then activate Energy channel. On subsequent turns, he could attack for 1d8+11(or 13) fire damage
(Caster level: Paladin level -3; use the trait magical knack to get +2 CL, so CL is Paladin level -1)

At level 20, he could have Channel Energy 10d6(16d6 with divine bond active), and hit with flame blade for 1d8+41 fire damage if he uses Energy channel.

[Movin]

A Samsaran warpriest could use flameblade to good effect.

Though holy ice weapon presents a viable second option if you want your character to go the strength route.
Downside is it hits normal AC but there is no SR.

[Vinyc Kettlebek]

For a homegame you could just make up a greater flameblade spell that deals more damage, or a feat/archetype that allows you to make a full attack action at higher levels with a flameblade.

[BadBird]

The Paladin option is tempting, but Paladin spellcasting is so weak that really focusing on Flame Blade is problematic.

Samsaran opens up options for other Classes, but I'm not sure other classes bring much more to the table when Shaman has access to all the spells I'm looking at, the Battle Spirit bonuses, and a way to gain channeling. I guess Samsaran Evangelist Cleric and Samsaran Druid would be worth another look.

I'm not sure how I glossed over Frostbite when first looking at Flame Blade, since stacking Frostbite onto Flame Blade touch attacks looks pretty great; it's not even a major action-economy issue when you've got Flame Blade running and you make the first free touch attack with Frostbite. Action economy overall seems clunky depending on how much pre-buffing is possible (so Quickening may be a must), but by the time things are coming together at Shaman 8 it looks like it's quite possible to be pushing a lot of damage between Flame Blade, Frostbite, Divine Favor, Battle Spirit and scimitar flurry.

I guess one of the biggest issues with trying to focus on Flame Blade is that a ton of resources need to be put into crushing Spell Resistance, since failing to beat SR with Flame Blade is kind of a disaster.

[SmiloDan]

Vinyc Kettlebek wrote:

For a homegame you could just make up a greater flameblade spell that deals more damage, or a feat/archetype that allows you to make a full attack action at higher levels with a flameblade.

Wait: You can't full attack with flame blade???

[Starbuck_II]

SmiloDan wrote:

Vinyc Kettlebek wrote:

For a homegame you could just make up a greater flameblade spell that deals more damage, or a feat/archetype that allows you to make a full attack action at higher levels with a flameblade.

Wait: You can't full attack with flame blade???

I think he mean a full BABer with it. Yes, you can full attack with it.

[Hubaris]

Nature Fang Druid with Variant Multiclass Rogue for a chunk of Touch Attack Sneak Attack on iterative attacks. Could even grab Accomplished Sneak Attacker to gain near perfect progression with Full Casting.
Works pretty well considering.

You would definitely need Elemental Spell (or Searing Spell from 3.5's Sandstorm) to deal with the eventual Fire Immunities.

Keep in mind Studied Target from Nature Fang increases Spell DCs against the Studied Target as well, allowing you to switch from your main schtick if you have to.

[Firebug]

Gozreh's Trident (electric trident "flame blade")
Startoss style +6 damage
Swashbuckler Precise Strike +(up to)20 damage
Swashbuckler Weapon Training +1-4 damage
Martial Focus (Thrown) +1 damage, and Ricochet Shot because you want to ricochet your regular trident against the electric immune critters anyway
Weapon Spec, Greater Weapon Spec: +2/4

Level 12 or so and you are looking at 1d8+1(scroll/wand CL/2) +6(startoss) +12(precise strike) +2(swash weapon training) +4(Greater weapon spec) +1(Martial focus) = 1d8 +26 and the only real differences from a flying blade type swashbuckler is ... not taking the flying blade archetype because its daggers and starknives only. Full BAB class, can off-turn attack with parry and riposte. So 4-5 attacks per round at 30.5 average noncrit (122 w/4 hits)

And you get to play (a dex based) Zeus.

Electric is less resisted then fire, so there is one advantage over flame blade. I'd argue that Flame Blade only crits 20/x2 due to the wording of Mythic Flame Blade, but that is a different conversation.

Doing an empowered Frostbite + empowered Gozreh's Trident on a full caster with 3/4 bab with startoss feats and skipping the precise strike is probably better overall damage though. But fewer attacks. I mean without doing too much, you are at least getting 3 attacks with haste for (1d6+12)*1.5 + (1d8+6)*1.5 +6(Startoss) average 45 per hit (135 w/3 hits), but you are likely burning a 3rd and a 4th level slot (without reducers) to do it every combat. Plus someone is casting haste, or you've got boots. And double resistance hits too on this version.

Edit: Actually, you probably need spellstrike to stack Frostbite and Gozreh's Trident. So that might be a bit less damage because of casting Trident from a scroll/wand.

[Dark Immortal]

Have you looked at this thread? It provides some useful ideas.

Currently, I am playing in a primitive themed game, with virtually no magic items and sporadic technology (think Numerian setting with technology being present in the form of crashed ships and scavenged items).

While not optimized this build can provide some useful angles to pursue.

Ashakari:

Ashakari, Cinder Dancer (25 point buy).

Male Samsaran Oracle 9 (Dual-Cursed/Warsighted), Fighter 2 (Lorewarden), Sorcerer 1 (Wild Blooded-Primal Elemental).
Mystery: Flame.
Curse: Powerless Prophecy, & Curse of Choice (Wrecker & Tongues are good).
Alternate Racial Traits: Mystic Past Life (Druid or Shaman).

Str: 7
Dex: 20 (boost at 4th and +2 implants).
Con: 10
Int: 13
Wis: 9
Cha: 18

Feats:
Dodge *, Mobility, Spring Attack.
Combat Expertise, Eschew Materials.
Dervish Dance, Weapon Finesse, Combat Reflexes,
Extra Revelation, Extra Revelation, Extra Revelation.

Flex Choices: Whirlwind Attack, Weapon Trick, Dedicated Adversary, Piranha Strike, Arcane Strike, Lunge, Two Weapon Fighting tree.

*We receive one bonus feat for free at level 1 due to the game being played in hard mode (enemies roll twice on everything and take the best result, we roll for all hp and keep- including first level, no magic items, enemies all have max hp per hd, no Metamagic feat access).

Revelations:
Cinder Dance, Fire Breath, Heat Aura, Form of Flame, Wings of Fire.

Spells:
You need Produce Flame and Flame Blade. These are taken from the Druid or Shaman spell list using your alternate racial trait Mystic Past Life. You have one more spell of import to select and it dictates which classes spells you want access to: Longstrider (Greater) or Spirit-Bound Weapon. You can't have both. :(

Greater Longstrider will give you a sweet +20 to movement speed to enhance your mobility in combat, making Spring Attack a lot more useful and keeping you safely out of many harm's way.

Spirit-Bound Blade will give you Improved Critical or the Vicious weapon property. Either way your damage will improved dramatically making you more of a threat and 'striker'. You can flex into or actually take Improved Critical at later levels to focus on just the Vicious property making you more lethal.

Longarm and Enlarge Person are useful, especially with Lunge, for making Whirlwind Attack cooler.

Moreover, Produce Flame is neat for making your two-weapon fighting stuff look pretty neat.

With magical item access in a normal game world, you are entirely capable of making far more efficient choices and do so earlier. You can free up more feats, etc.

Traits:
Elemental Pupil
Magical Knack
(take a flavorful drawback and add another trait).

In the end, I went with flavor and theme first, over practicality and combat effectiveness. But I did try to get a nice blend. Remember, many of these suggestions are made in the absence of normal circumstances. With metamagic feats you can do so much more. Due to restrictions on which classes were available in the game and the stringency to which religious, organizational, and other labeled systems are being held, I could not be more efficient with say, a level of Dervish of Dawn Bard for an additional +2 to hit and damage, two free feats from our list (making for more available to take or more revelations).

Either way, apologies for the delay in my reply. I saw this about a week ago and had forgotten to reply earlier. Hopefully this gives you some inspiration.